Radial flow forced-air heater



1%48. H|GLEY 2,453,913

RADIAL FLOW FORCED-AIR HEATER Filed Aug. 28, 1943 v 2 Shepts-Sheet lINVEN TOR.

FEW/w F. 19/645) BY Nov. 16,, E948. HlGLEY 2,453,913

RADIAL FLOW FORCED-AIR HEATER Filed Aug. 28, 194s 2 Sheets-Sheet 2 1 INVEN TOR. FA-w/vk 1E. H/GLEY Patented Nov. 16, 1948 RADIAL FLOWFORCED-AIR HEATER Frank R. Hlgley, Cleveland, Ohio, assignor to BryantHeater Company, a corporation of Ohio Application August 28, 1943,Serial No. 500,387

This invention relates to improvements in forced air heaters in whichthe air to be heated is driven by a centrifugal blower through anannular diffuser at least one wall of which is heated, the apparatusincluding preferably a power burner arranged to move products ofcombustion over an outer surface of the diffuser in parallel flow withthe moving air, that is to say parallel flow as distinguished fromcounterflow.

One of the objects of the invention is the provision of a heater ofrelatively small size and weight with a minimum of moving parts.

Another object is the provision of a heater which is adaptable forinstallations of varying character in which the available vertical spaceis small.

Still another object is the provision of a power gas burner of novelconstruction.

Other objects and features of novelty will appear as I proceed with thedescription of those embodiments of the invention which, for the purposeof the present application, I have illustrated in the accompanyingdrawings, in which Fig. 1 is a central vertical sectional view of aheater embodying the invention;

Fig. 2 is a plan view of the same partially in section along the line 22of Fig. 1; V

Fig. 3 is a bottom plan view partially in section along the line 33 ofFig; 1; and

Figs. 4 and 5 are small scale elevational views showing differentdispositions of the driving motor.

The heater of the present invention is a compact apparatus with arelatively small axial dimension as compared with its lateraldimensions, and is particularly adapted for installation beneath theceiling or beneath the floor of a room or rooms to be heated. The air tobe heated and 6 Claims. (Cl. 126-110) the gas and air mixture to beburned are both 2 ity decreases in similar ratio, so that maximum heattransfer is effected. The heated air may be collected in a plenumch'amber surrounding the diffuser, and the warm air ducts extendradially outward from the perimeter of the plenum chamber, so thatmaximum eii'ect of the lmpelling force of the air blower is maintained.v

In the drawings the heater is shown as comprising two principalcastings. The upper one includes an annular partition l0 upon the upperside of which there are a series of vanes I I, I2 and l3 of the sameheight but of different lengths, as

illustrated in Fig. 2. A cover it rests upon the vanes ll, I2 and i3andwith the annular partition Iii constitutes a diffuser.

On the bottom side of partition l0 there are fins.l5, l6 and I1 disposedopposite the fins Ii, l2 and I3 respectively. These bottom fins are ofless height than the fins I l, l2 and I3, and engage the upper surfaceof a heat insulatin and reflecting annular body l8, which may be in asingle piece or in a series of like sections. Memlber l8 rests in aconcavity of a second casting 20 which has an outer annular wall 2! thatmeets 'a down turned flange 22 on the upper casting,

the meeting surfaces being machined and the outer edge of the uppercasting being secured to the lower one by a plurality of bolts 23extending through perforated lugs 24 on the upper casting and through aflange 25 on the lower one. An annular wall 280! the lower casting ismachined to meet an annular flange 21 near the inner edge of the uppercasting, the latter flange having a series of notches 28 formed thereinconstituting burner port means of circular form. The circular opening atthe center of the annular partition I0 is closed by a disk 29 whichbears against the under-surface of partition Iii inside the flange 21.Bolts 30 extend through the partition ID, the disk 29, separators 3| andbosses on the lower casting 20, whereby these parts are all securedtogether.

Casting 20 has a downwardly and inwardly flared wall 32- which with thedisk 29 and the flange 21 forms a mixing chamber 33 that is closed atthe bottom by a plate 34 except for a small central air intake opening35 in the plate.

The products of combustion after leaving the burner ports 28 traveloutwardly between the partition Hi and the insulating and heatreflecting body II and are collected in a conductor 38 which increasesin depth gradually toward an outlet 31 leading to a flue, not shown.Since the fins l5, i6, i1 impart a swirl to the emerging combustionproducts, the collecting conductor 36 is preferably given volutecharacteristics as indicated in Fig. I.

The cover I4 extends down along the sides of the heater to meet theflange 25 of the lower casting, forming a plenum chamber 40, which isillustrated as having va square perimeter. The number of sides may beincreased as desired however. Warm air conduits 4i extend outwardly atright angles from as many ofthese sides as the requirements of aparticular installation dictate. The warm air leavin the diffuser canthus flow directly into these conduits without deflection and withoutgiving up any of the impetus which it receives from the impelling force.

An upwardly dished ring 42 partially bridges the circular space at thecenter of the cover l4, being attached by means of studs 43 or the likeextending through holes in the cover into bosses formed in certain ofthe vanes I I. This ring carries brackets 44 upon which is mounted anelectric motor 45, the shaft 46 of which extends downwardly at the axisof the heater and through a hole in the disk 29. The latter disksupports a bearing 41 for the shaft. A centrifugal blower wheel 48 issecured to shaft 46 above bearing- 41, the wheel being open at the topto correspond with the opening in ring 42, and being closed at thebottom by an end wall 49 which is welded or otherwise fastened to acollar 50 by means of which the wheel is secured to the shaft. Theblades of the wheel and the vanes H, l2 and I3 are so related angularlythat the air impelled by the wheel tends to flow outwardly between thevanes with a minimum of friction.

n the shaft 46 below the disk 29 there is mounted a second centrifugalblower wheel 51 of comparatively small size, this wheel being open atthe bottom and closed at the top by a circular plate 52, which isattached to a collar 53 that surrounds the shaft and is secured thereto.

Plate 34 at the bottom of the mixing chamber carries a downwardly offsetcentral hub member 54 which is threaded to receive an externallythreaded tube 55 that extends upwardly into close proximity with the endof shaft 46, thereby forming an annular gas port. The width of this portmay be adjusted by threading the tube 55 upwardly or downwardly, and theparts may be held in adjusted position by means of a lock nut 55.Asuitable gas conductor 51 connects with the lower end of tube 55. Gasentering through tube 55 and air entering through opening 35 are drawnto the center of wheel and 1 expelled centrifugally, being thoroughlymixed in the wheel and in the chamber 33. Flowing through the ports 28,the mixture burns in a circular flame pattern outside the ports. I thusprovide a power burner of simple design and low cost, the flame of whichis applied to the partition l0 beneath the entrance to the diffuserwhere the velocity of air travel is at its maximum. The cooling effectof the rapidly moving air thus prevents the temperature of the partitionat this point from becoming, excessively high.

In Figs. 4 and 5 I have illustrated two different motor mountings usingflexible belt drive means to the shaft 60 for the blower wheels. In Fig.4 I have shown a bracket 6i carried upon the heat- 'er, the motor 62being bolted to the side of this bracket. By this means the motor issupported approximately in the plane of the heater, reducing the overall vertical dimension to a minimum.

-4 In Fig. 5 the member 63 is supported upon the heater in a positionoffset from the axis. This arrangement is excellent where the heater isto be installed beneath a floor, for then the motor as well as the upperend of shaft with its pulley and upper hearing may be accommodatedbetween I adjacent floor joists.

Having thus described my invention, Iclaim:

1. In a heater, a heat exchange partition, a centrifugal wheel formoving air divergently over one surface of said partition, means coaxialwith said wheel for moving products of combustion divergently over theopposite surface of said partition, said partition having opposed finson the two surfaces thereof, said fins being disposed in the directionof discharge from the wheel.

2. In a heaterja combustion chamber one wall of which constitutes a heatexchange partition and the opposite wall of which has heat reflectingand insulating 'propertiea rotary means for moving products ofcombustion through said combustion chamber divergently along one surfaceof said partition, and coaxial rotary means for moving air divergentlyover the opposite surface of the partition.

3. In a heater, two coaxial centrifugal blower wheels means providingseparate compartments therefor of substantially equal radial dimensions,one wheel being relatively large and the other relatively small, thecompartment for said large wheel having a central air intake and thecompartment for said small wheel having substantially central gas andair intakes, the space within the latter compartment outside of saidsmall wheel constituting a mixing chamber, said small wheel compartmenthaving burner ports oppo-. site the discharge from the large wheel, andan annular heat exchange partition over the opposite surfaces of whichair from the air blower and products of combustion from the flame atsaid ports flow divergently.

4. In a heater, a combustion chamber one wall of which constitutes aheat exchange partition, means for moving products of combustion throughsaid combustion chamber divergently over one surface -of said partition,means for moving air divergently over the opposite surface of thepartition, said partition and said means for moving air and combustionproducts being distributed about a common axis, and means arrangedperipherally of the combustion chamber for collecting the products ofcombustion and having a flue outlet.

5. In a heater, a combustion chamber one wall of which constitutes aheat exchange partition, means for moving products of combustion throughsaid combustion chamber over one surface of said partition, means formoving air. in parallel flow therewith over the opposite surface of thepartition, said partition and said means for moving air and combustionproducts being distributed about a common axis from which divergent flowof air and combustion products takes place, and means of volute formarranged peripherally of the combustion chamber for collecting theproducts of combustion and conducting them to discharge outlet means.

6. In a heater, a combustion chamber one wall of which constitutes aheat exchange partition, means for moving products of combustion throughsaid combustion chamber over one surface of said partition, means formoving air in parallel flow therewith over the opposite surface of thepartition, said partition on the combustion chamber side having finsdisposed in a non-radial direction corresponding to the direction ofdischarge from the wheel, said partition and said means for moving airand combustion products being distributed about a common axis from whichdivergent flow of air and combustion products takes place, and means ofvolute form arranged peripherally of the combustion chamber forcollecting the prodnets of combustion and conducting them to dischargeoutlet means.

FRANK R. HIGLEY.

REFERENCES CITED The following references are of record in the flle ofthis patent:

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